Field of the Invention
The present invention relates to a recording medium, an information processing apparatus, and a control method and, more particularly, to a technique of presenting a 3D representation by geometric deformation of a 2D image.
Background Art
In recent years, in the field of computer graphics represented by a game content, it has become possible to present an image which allows an observer to perceive a sense of depth and a stereoscopic effect using a 3D model. In such 3D graphics, in general, a 3D model is constructed based on a plurality of 2D images (cuts) prepared by a designer or the like, and a texture is applied to the model, thereby performing rendering.
In 3D graphics rendered by applying a texture, however, even if the 3D structure of a 3D model is represented by using a technique such as tessellation, an image rendered by applying a texture to the model may give an impression different from the cut initially prepared by the designer or the like. This is because it is difficult to obtain such effect in an image of 3D graphics “correctly” rendered with respect to a specific viewpoint by applying a texture to a model, as compared with a 2D image in which the designer readily reflects an effective appearance to the observer. More specifically, for example, in animation or a cartoon, inconsistent performance representation or so-called “unrealistic” representation can be performed for a characteristic portion such as a hairstyle, a contour, or clothing represented as the personality of a character so that the characteristic shape appears even if the character faces in any direction. On the other hand, in 3D graphics, since a 3D model is basically fixed, such representation is difficult, and an image of the character which gives an impression different from that intended by the designer is resultantly presented. In recent years, rendering representation close to animation has become possible by applying toon rendering technique or toon shader. However, such rendering representation requires fine adjustment, and tends to increase the calculation amount necessary for rendering. An apparatus capable of rendering graphics can be limited to a high-performance rendering apparatus such as a so-called next-generation apparatus.
Furthermore, a 2D image handwritten by the designer has the appeal of the representation unique to the 2D image. Although 3D graphics are becoming the mainstream, a game content or the like in which a 2D image is mainly used in a game screen has been supported to some extent. Japanese Patent Laid-Open No. 2009-104570 discloses a rendering technique capable of representing 3D animation while maintaining the atmosphere and appeal of a 2D image rendered by a designer. More specifically, in Japanese Patent Laid-Open No. 2009-104570, after dividing a 2D image into parts such as hair, eyebrows, and eyes, a predetermined 3D shape is assigned to each part and, in accordance with movement of a base part, geometric deformation of the 2D images of the remaining parts is defined, thereby implementing representation desired by the designer without damaging the impression of the original 2D image.